There is often demand for providing efficient overload protection in semiconductor devices, like for example power field-effect transistors. This may, for example, be done by embedding a sensor structure which exemplarily detects a sensor current, wherein this sensor current is proportional to a current through the power field-effect transistor, in a field of cells of a power field-effect transistor. When the sensor structure is embedded in a field of cells of the power field-effect transistor such that the leads are perpendicular (or parallel) to one of the sides of the field of cells/chip and/or the direction of trench stripes, the result may be semi-floating potential (body) regions along the leads. The semi-floating potential regions may, depending on the embedding depth of the sensor structure, be considerably longer than 200 μm or even be in the range of mm. Semi-floating potential regions are taken as regions which are geometrically long but not formed as an area, but only connected to a defined potential at the ends. With fast voltage pulses having very steep edges (like for example ISO pulses or ESD (electrostatic discharge) events), the result may be that the potential along such a semi-floating region and/or semi-floating potential region is dynamically strongly different. Close to contact points, the potential will follow the set value very quickly, however at the remotest position, it may still dynamically exhibit an unfavorable potential value such that gate oxide stress or even voltage breakdowns and damage may occur in neighboring trenches. Reliability risks and, in the worst case, local destruction of the power transistor are the results.
Embodiments thus deal with the field of optimum embedding of sensor structures in a large-area field of cells of a power transistor.
For these and other reasons, there is a need for the present invention.